i have no idea thats the thing the guy that had it before me traded it in and i bought it from a local dealer who doesn't know cars.

the car would not run rich/lean without throwing a code. if you have a bad o2 sensor on there, u should def. have a code for that and it would change how your engine runs because its not getting info from the sensor.

If you don't have a MIL and the car seems to drive fine, leave it alone.

i have a code for the o2 sensor but nothing else.

you see, when someone asks "do you have any codes?" - 'no' would be the wrong answer if you do have a code.

now -what is the code exactly? P0xxx

what is the A/F ratio then?

and you have yet to provide any details about which car you are talking about. year, engine (assuming a 1.8t), transmission, quattro/fwd. the standard stuff when asking mechanical questions.

I thought they meant codes mentioning running lean. my mistake. i forget ill look at it later.